PubMed Health⌕ Search

Biomedical subjects

A M Dupin

Publications and source records attributed to A M Dupin.

29 records · Page 2Linked to original sources
PubMed1988

The level of natural antioxidant glutathione and histidine-containing dipeptides in skeletal muscles of developing chick embryos.

1. The levels of glutathione and histidine-containing dipeptides in skeletal muscles change in different ways during ontogenesis. 2. The glutathione content in skeletal muscles increases between the 9th and 18th days of embryongenesis--from 0.5 to 2.0 mumol/g of tissue wet wt and then drops to zero in 3-week-old chickens. 3. The level of histidine-containing dipeptides increases throughout the observation period beginning with their appearance on the 14th day in leg muscles and on the 15th day in breast muscles of chicken embryos up to the 21st postnatal day. 4. There is a negative correlation between the antioxidative systems of glutathione and histidine-containing dipeptides in muscle tissue, i.e. dipeptide-rich tissues contain little or no glutathione and vice versa.

Animals↗
PubMed1987

The antioxidative properties of carnosine, a natural histidine containing dipeptide.

The experimental results suggest that the antioxidative function of carnosine is one of the most important manifestations of its biological role. The ability of carnosine to interact directly with lipid peroxidation products was demonstrated. The effects of carnosine on partial restoration of lens transparency in dog eyes with senile cataract which is known to be caused by lipid peroxidation were demonstrated "in vitro" and "in vivo".

Animals↗
PubMed1987

[Muscle dipeptides--natural inhibitors of lipid peroxidation].

The effects of carnosine (beta-alanyl-L-histidine) and anserine (beta-alanyl-1-methyl-L-histidine) on ascorbate-dependent lipid peroxidation in frog skeletal muscle sarcoplasmic reticulum were studied. It was found that the dipeptides (10-50 mM) cause a 25-90% inhibition of ascorbate-dependent lipid peroxidation and decrease the reaction rate and the amount of end products. The nature of lipid peroxidation primary products in the presence of the dipeptides changes which can be evidenced from changes in their spectral properties. Unlike other known natural antioxidants, skeletal muscle dipeptides do not only inhibit lipid peroxidation but also decrease the level of accumulated lipid peroxidation products. Histidine and beta-alanine, similar to imidazole, glycyl-glycine, arginyl-phenyl alanine and alpha-alanyl-D-histidine do not inhibit lipid peroxidation. At the same time, the carnosine stereoisomer D-carnosine which does not exist in nature exhibits a far greater inhibiting effect as compared to its natural counterpart. It is assumed that the skeletal muscle dipeptides carnosine and anserine are highly effective as natural antioxidants.

Animals↗
PubMed1986

[Changes in carnosine levels in muscles working in different regimens of stimulation].

Carnosine content in muscles functioning under single or tetanic (both direct and indirect) contractions, in the period of active contractility (within the first 10 min of experiment) and in fatigued muscles was determined. In exercising muscle, carnosine content was shown to decrease. The loss of the dipeptide during active contractions was, on the average, 10.5%; that at fatigue--13.8%. At exercise (single contractions), the decrease of carnosine was higher than in the muscles functioning in a short tetanus regime. It was shown that the previously described phenomenon of fatigue elimination by carnosine addition to the Ringer solution washing the muscle is concomitant with the elevation (by 12%) of the intramuscular concentration of exogenous carnosine.

Animals↗
PubMed1984

[Carnosine protection of Ca2+ transport against damage induced by lipid peroxidation].

The authors studied the protective action of carnosine on sarcoplasmic reticulum (SR) membranes from frog skeletal muscles destroyed by ascorbic acid-dependent lipid peroxidation (LPO). It was demonstrated that addition of carnosine to the incubation medium at a concentration of 25 mM sharply decelerated inactivation of Ca-ATPase of SR membranes, maintaining at the same time the coupling of hydrolysing and transport functions of the Ca-pump. When given at the same concentration carnosine inhibited the accumulation of LPO products reacting with 2-thiobarbituric acid. This effect of carnosine was followed by its utilization.

Animals↗
PubMed1979

[Role of lipids in regulation of microsomal glucose-6-phosphatase activity after modification of mcirosomes in vivo and in vitro. Effect of phospholipid effectors on the activity of glucose-6-phosphatase].

Modification of microsomal membranes in vivo and in vitro results in changes of the glucose-6-phosphate and inorganic pyrophosphate phosphohydrolase activities of liver microsomal glucose-6-phosphate phosphohydrolase (EC 3.1.3.9). It was demonstrated that the glucose-6-phosphate phosphohydrolase activity of glucose-6-phosphatase depends on the content of phosphatidylethanolamine in the microsomal membranes, whereas the inorganic pyrophosphate phosphohydrolase activity seems to be dependent on the phosphatidylserine content. It is assumed that the regulation of the corresponding enzyme activities by these phospholipids is performed by the same allosteric mechanism in vitro and in vivo.

Animals↗
PubMedDate not supplied

The state of the serotonin transporter protein in the platelets of patients with somatoform [correction of somatiform] disorders.

The role of the serotonin transporter protein (STP) in the development of somatoform [corrected] disorders was addressed in a correlational study of the levels of immunoreactive STP (IR-STP) using site-specific antibodies against the least conserved (among a group of other cotransporters) epitope at the C-terminal of STP and the level of anxiety symptoms in patients with somatoform [corrected] disorders. A total of 22 patients were studied, with DSM-IV diagnoses of somatoform [corrected] disorders, along with 32 mentally healthy subjects of comparable age and sex. Immunoblotting of IR-STP from patients from healthy donors produced a diffuse band between 68 and 105 kDal and a clear narrow band at 43 kDal. The 43-kDal IR-STP protein was almost completely absent from most patients, as compared with the levels of this protein in healthy donors. This result suggests an abnormality of STP processing or, perhaps, alternative splicing of the gene encoding STP in patients with somatoform [corrected] disorders, and this appears to reflect the dysfunction in serotoninergic transmission in the CNS in these patients.

Adult↗
PubMedDate not supplied

[Decrease in the platelet level of 43 kDa immunoreactive fraction of serotonin transporting protein correlates with depressive symptoms in patients with somatoform disorders].

To elucidate the role of serotonin transporter (SERT) protein as a candidate target for somatoform disorders (SD), we have performed an association study of the SERT immunoreactive (IR-SERT) protein level by using site-specific antibodies directed at C-terminus epitope poorly conserved among other cotransporters. 22 patients who met DSM-IY criteria for SD and 32 healthy volunteers matched in sex and age participated in the study. In platelets from all healthy donors, IR-SERT proteins migrates as a diffuse band between 75 and 102 kDa and a major sharper band at 43 kDa. We revealed almost complete disappearance of platelet 43 kDa IR-SERT protein in all patients with SD. All patients were rated with Hamilton Depressive Rating Scale (HDRS). There were found a significant negative correlation between residual IR-SERT 43 kDa protein level and HDRS Scores [r = -0.83; P < 0.000001]. These findings suggest that a biosynthetic or processing abnormality may exist in SERTs in the affected population and may reflect the dysfunction of serotonin neurotransmission in CNS.

Adult↗
PubMedDate not supplied

[Biological role of histidine dipeptides in excitable tissues].

The biological role of the histidine dipeptide carnosine in the cells of olfactory bulb and muscular tissue was studied. In the muscle, carnosine directly interacts with peroxides formed in the tissue that deteriorate the structure and function of membranes, and participates in maintaining the muscle in a functionally active state.

Animals↗
PubMedDate not supplied

[Erythrocyte membrane permeability for monovalent ions in pubertal juvenile dyspituitarism].

Red cell membrane permeability was studied in 46 patients with pubertal juvenile dyspituitarism by measuring the rates of Na+/H,-Na+/Li(+)-metabolism, Na(+)-K(+)-contra-transport. The reference group consisted of 25 healthy adolescents and youths whose heredity was not aggravated for essential hypertension. No significant differences in the membrane permeability for monovalent cations in the reference subjects and the patients with the pubertal juvenile dyspituitarism were revealed. Thus analysis of the membrane characteristics may be helpful in the differential diagnosis of hypertension.

Adolescent↗